Message from the Editor-in-Chief

What Parameters Can We Allow the Musician To Self-Adjust?

I am frequently asked by my musician clients if they can have control over my software programming when fitting and adjusting their hearing aids. At this point I usually look over my glasses frame and with my best paternalistic look, I say “no.” At this point they get impatient with me until I explain in a calm and professorial voice and say “you are too stupid to understand what you will be doing.” And, for some unexplained reason, they either storm out of my office, or more often, hurl some really colorful words in my general direction.

But now after years of having this happen to me, perhaps I am wrong? Perhaps musicians (and indeed the general hard of hearing public) do know about some things that I don’t? Perhaps they can do as good a job as I can? This has implications, not only for musicians, but for anyone who can gain access to Internet-based software tools and can find a way to program their hearing aids (or smart phones).

We are already in an era where Internet-based software can be used to allow a person to adjust their personal amplifiers, or even Personal Sound Amplification Products (PSAPs), using some mode of coupling, possibly via their smart phone with Bluetooth-enabled PSAPs.

Short of abrogating all of my responsibilities as an audiologist, what are some electro-acoustic parameters that I wouldn’t mind giving up control over – perhaps something that they could experiment with at home and while playing music … something that would not allow the aided musician to experience any “harm.”

The one parameter I would not give up control over is the maximum output of the hearing aids (OSPL90). This parameter has to be fit according to an individual’s frequency specific tolerance levels and I this is something that only a hearing health care professional can fit.

As far as the other parameters are concerned – compression characteristics, frequency response, and gain settings, I am a bit more “casual” about. After all, the worst case scenario is that the hard of hearing musician is back in my office with their tail between their legs.

Setting gain is really no different than setting the volume control on their radio. Setting the compression characteristics – albeit more complex than gain – is also something that hard of hearing musicians can “play” with in various listening environments. If they indeed did have control over the amount of gain for soft, medium, and loud sounds they could experiment for hours – something that a typical clinician would not have time for. We could make it really easy, but just giving them control over the compression ratio, which given the gain, and pre-selected output, they could play with in various frequency bands. And we can suggest some “guiding principles for music” such as never let the compression ratio exceed 3.0; use similar attack and release settings for both speech and music; set the gain and the maximum output for the music program to be about 5–6 dB lower than that chosen for the speech-in-quiet program.

Frequency response is even simpler and virtually every single musician, or audiophile, I have ever seen have played extensively with the settings on their home MIDI system. The reason for it being a simple setting is that there is no inherent reason for the frequency response of a “music program” to be set any differently than that for any of the various speech programs. The frequency response has more to do with the audiometric features rather than the nature of the input to the hearing aids.

I would even offer to give them a quick summary based on the work of doctors Todd Ricketts and Brian Moore, for more mild losses, and those losses with gradually sloping audiometric configurations, set the frequency response settings as wide as possible (i.e., more is better). For more severe losses (> 60 dB HL) or if the audiometric configuration was steeply sloping, then a frequency response that has limited high end would be better (i.e., less is better). This has nothing to do with the nature of the speech or music entering the hearing aid.

If indeed, a complete audiometric assessment was performed, the resulting frequency response for a speech program can be set, and then the musician will be free to play with the frequency response for the music program. I would be willing to wager that the ultimate frequency response (given the limitations of modern hearing aids) for the music program would be similar to that of the yet-to-be-programmed music setting, and identical to that of the speech-in-quiet program.

So, to allow a musician to set-up their own music program, really all an audiologist would need to do to is:

Educate the musician in some general audiological principles

Pre-set the OSPL90

And, maybe set the parameters for the speech-in-quiet program.

I know that some out there would find this heretical and my gut tells me that this is also the case, but I think that a discussion of these issues is worthwhile before too many more clients walk in to our offices demanding more control over some aspect of their hearing aid fittings.

About the Editor in Chief

Marshall is the director of research at the Musicians' Clinics of Canada and has presented and published extensively on the topics of hearing loss prevention in musicians and hearing aids for music.

Other than being the editor in chief of Canadian Audiologist, Marshall Chasin writes a regular column in the Hearing Review called Back to Basics. Some of these columns are reprinted in this issue of Canadian Audiologist with permission of the Hearing Review.